Adjustable strap connector



J1me 1965 A. Y. WARNER ETAL 3,189,953

ADJUSTABLE STRAP CONNECTOR Filed Dec. 29. 1961 INVENTORS ALDEN Y. WARNER WILBUR J. CRAVEN JOHN STACHERL ATTORNEYS United States Patent Ollice EJ893555 Patented June 22, 1965 3,189,963 ADJUSTAEILE STRAP CflNNEiITQR Alden Y. i'iarner, l armington, Wilbur .li. Qraven, East Hartford, and John Stacherl, New hritain, Conn, assiguors to The Capewell Manufacturing Company, Hartford, (Tenn, a corporation of Connecticut Filed Dec. 29, 196i, er. No. 163,255 r 5 (Ilaims. (til. Ed -196) This invention relates to belt or strap connectors, and more specifically to an improved belt or strap connector for adjustably securing the end of a strap or Webbing and having particular utility in safety belt buckles.

One of the objects of the present invention is the provision of an improved adjustable strap connector which will effect a secure connection capable of successfully withstanding relatively great loads even when suddenly applied thereto and of insuring against slippage of the strap both under heavy loads which highly tension the strap and under relatively small loads.

Another object is the provision of an adjustable strap connector which will prevent slipping of the strap therein under heavy loading without injurious abrading or cutting of the strap, and, consequently, without diminishing the strength or margin of safety of the strap even after extended usage.

A further object is to provide such an improved adjustable strap connector which can be easily manipulated and which is relatively simple in construction and which may be readily and economically fabricated and assembled.

Gther objects will be in part obvious and in part pointed out more in detail hereinafter.

The invention accordingly consists in the features of construction, combination of elements and arrangement of parts which will be exemplified in the construction hereafter set forth and the scope of the application which will be indicated in the appended claims.

In the drawings:

FIG. 1 is a perspective view of a safety belt buckle assembly embodying the present invention wherein the strap has been broken away for purposes of clarity;

FIG. 2 is a fragmentary side elevational view of the safety belt buckle of FIG. 1 with the side wall partially broken away to show the operative elements of the strap connector in a strap-adjusting position; and

FIG. 3 is a view generally similar to FIG. 2 showing the operative elements of the strap connector in straplocking position.

Referring in detail to the attached drawings, a safety belt buckle embodying the present invention is generally comprised of the frame unit or buckle designated by the letter A and the separable fitting designated by the latter B and which is engageable in the forward end of the buckle A to connect together the two straps 2 and 4. The end portion of the strap 2 is looped through the aperture 6 of eparable fitting B and then the overlapping portions secured together (not shown) in any convenient manner such as stitching to thereby permanently position fitting B therebctween.

The buckle A has an elongated, generally channelshaped frame 8 with a bottom wall It? and integral upstanding side walls 12 and 1d. The latch cover 15 is pivotally mounted on the side Walls 12 and 14 by pivot pins 13 and encloses suitable latching mechanism for firmly engaging the separable fitting B, the illustration of which has been omitted for purposes of clarity. A high- 1y effective latching mechanism is illustrated in detail in our Patent No. 2,999,288 issued September 12, 1961.

- Referring now in detail to the rearward portion of the buckle A which is constructed in accordance with the present invention to provide an adjustable connection for the end of the strap 4, the bottom wall 1% of the frame 3 has a transverse strap-receiving aperture 2% providing a stationary gripping face 21. Slidably carried in the frame it above the aperture 2% is a cross member 25 which has projectins end portions 26 loosely received in parallel, generally longitudinally extending slots 23 in the side walls 112 and 14. As can be seen in FIGS. 2 and 3, the plane of the bottom surface of the cross member 25 is spaced above but closely adjacent the bottom wall lid. The periphery of cross member 25 is defined by a plurality of discontinuous and generally alternating flat and convex surfaces (for a purpose to be described more fully hereinafter) including the movable convex gripping face 2'7 at its lower rearward edge cooperablc with the stationary gripping face 21 and the gripping shoulder 22 on the upper surface of the bottom wall it) adjacent thereto. Spaced upwardly of the gripping face 27 is the projecting ledge portion 29 which extends rearwardly of the frame and has a convex outer surface 30.

The slots 23 in the side walls 12 and 14 are dimensioned to permit the cross member 25 to move from a position forwardly of the stationary gripping face 21 to a position wherein the ledge portion 29 extends rearwardly thereof. As best seen in I63. 2 and 3, the slots 23 also are slightly inclined rearwardly and downwardly of the frame 8 and are dimensioned sufficiently larger than the end portions 26 to permit limited pivotal movement of the elongated cross member end portions 26, and thereby the cross member 25, about their longitudinal axis while preventing rotation thereof for a purpose to be fully described hereinafter.

Although the desired peripheral configuration of the cross member 215 may be provided in a single element by extrusion or machining, the cross member 25 is most conveniently fabricated from a body portion 32 and a bar portion 34 press fitted into a longitudinal groove 36 in the body portion 32 as shown in the illustrated embodiment. The bar portion 34 is of sufficient. length so that its ends project beyond the ends of the body portion 32 to provide the end portions 26 of the cross member 25 which project into the slots 23. This two-piece construction permits the cross member 25 to be economically and etficiently fabricated and assembled to the frame 8 by first seating the ends of the bar portion 34 in the slots 23 and then press fitting the bar portion 34 into the longitudinal groove 36 of the body portion 32.

The surface of the cross member 25 is smooth and unknurled or otherwise roughened to eliminate abrasive action upon the strap 4, although a desirable increase in frictional engagement is preferably provided by utilizing a body portion 32 of aluminum having an anodized surface. in such a construction, the bar portion 34 of the cross member conveniently is formed from. chrome-plated steel for optimum strength, although the bar portion may be formed integrally with the body portion 32 if so desired.

in assembly, the free end portion 4 of the strap 4 is inserted upwardly through the strap-receiving aperture 29 forwardly of the cross member 25', looped over and around the cross member 25, passed out the strapreceiving aperture 2%) and double back upon itself so that the free end portion 4 of the strap overlies the continuous or main body portion thereof.

When tension is applied to the continuous or main body portion of the strap 4 as denoted by the arrow T in PEG. 3, the cross member 25 slides rearwardly of the frame 8 in the direction of the stationary gripping face 25 and into the position shown in FIG. 3. During this movement, the ledge portion 2? of the cross member 25 forces the strap irearwardly of the stationary gripping face 21 and the strap is firmly clamped between the movable gripping face 27 at the lower rearward edge of the cross member 25 and the adjacent surfaces of the stationary gripping face 21 and gripping shoulder 22. The displacement of the strap 4; rearwardly of the stationary gripping face 21 by the ledge portion 29 causes the strap to infiect about the edge of the shoulder 22 thereby increasing the wedging action and area of wedging provided by the cooperating surfaces. As can be appreciated, the greater the tensioning force applied to the strap, the greater will be the wedging or clamping force exerted upon the strap between the cooperating gripping surfaces 21, 22 and 27.

As previously pointed out, the slots 23 are dimensioned to permit limited pivotal movement of the cross member 25 about its longitudinal axis. Upon the application of tension to the strap 4, the cross member 25 pivots counterclockwise (as viewed in the drawings) so as to slightly elevate and position the movable gripping face 27 of the cross member 25 above the cooperating stationary surfaces 21, 22 to provide optimum gripping of the strap 4 without significant abrasive action. The upper edge of the stationary gripping face 1 1 is most desirably provided with a slight radius, as shown in the drawings, to

minimize abrasive action most conveniently by tumbling the frame with abrasives during fabrication.

Additionally, tensioning of the strap causes that portion of the strap looped around the cross member 25 to conform closely to the peripheral shape thereof with the result that a plurality of inflections E, F, G, and H are formed in the strap 4 which increase the frictional engagement therebetween and thereby reduce and tendency of the strap to slip thereover. Although the strap 4 is subject to great slip-resisting inflection under tension, the convex surfaces about the periphery of the cross member 25, includin the ed e 39 of the ledge ortion,

are not sharp or abrasive and, hence, provide firm ongagment of the strap without the use of abrasive knurling or cutting edges heretofore employed. Additionally, the relatively abrasion-free nature of the entire surface of the cross member 25 as aforedescribed effectively avoids abrasion and rapid wear on the strap.

This cooperation of the clamping of the strap 4 between the movable gripping face 27 and the stationary gripping face 21 and shoulder 22 and the multiple ini'lection of the strap under high tension about the remainder of the cross member 25 is highly effective even under heavy loads. Safety buckles embodying the illustrated embodiment of the invention have prevented slipping of the strap even when tensioned by a force of approximately six thousand pounds, but, although providing such firm retention of the strap against slippage, have not abraded the strap so as to materially lessen the strap strength and life. 7

In order to adjust the strap 4 so as to decrease the effective length thereof, the free end portion 4' is merely drawn through the buckle to the desired position. To quickly and easily increase the effective length of the strap, the buckle is tilted relative to the strap in a counterclockwise direction, as viewed in the drawings, and the continuous portion of the strap is merely pulled through the buckle in the direction of the arrow T and into the desired position.

As will be apparent to persons skilled in the art, various modifications and adaptations of the structure abovedescribed will become readily apparent without departure from the spirit and scope of the invention, the scope of which is defined in the appended claims.

, We claim:

, ,1; An adjustable strap connector comprising an integrally formed channel-shaped frame having a botton Wall and a pair of upstanding side walls, said bottom Wall having a transverse strap-receiving aperture therein providing a transversely extending stationary gripping face and said side walls having parallel, generally longitudinally extending slots therein; anda cross-member extending transversely of said frame between said side walls, said cross-member being comprised of a body member having a transverse groove in the side thereof adjacent said stationary gripping face and a bar member fixed in said groove and projecting outwardly thereof to provide a projecting ledge portion, said bar member being of greater length than said body member and having its ends freely extending into said slots to'slidably mount said cross-member for limited longitudinal movement in said frame with the plane of the bottom surface thereof spaced above but closely adjacent to the plane of the top surface of said bottom wall, said body member having a periphery providing a plurality of discontinuous convex and fiat surfaces including a convex lower edge adjacent said stationary gripping face to provide a second gripping face cooperating therewith below said projecting ledge portion, said projecting ledge portion having a convex outer face, said cross-member being slidable longitudinally relative to said stationary gripping face from a position away from said stationary gripping face to a position wherein said projecting ledge portion extends longitudinally beyond and overlies said stationary gripping face and said second gripping face is disposed above and closely adjacent thereto, said slots being dimensioned to permit limited pivotal movement of said cross-member about its longitudinal axis and being inclined downwardly towards said stationary gripping face, said cross-member being movable upon the application of force to the continuous portion of a strap received in said connector by passage upwardly through said strapreceiving aperture past the projecting ledge portion of the cross-member and thence around the cross-member and outwardly of the aperture to force the strap toward the stationary gripping face and pivot the cross-member about its longitudinal axis and clamp the strap firmly between the stationary gripping face and the convex gripping face of the body member, said discontinuous fiat and convex surfaces providing a plurality of slip-resisting inflections in the strap.

2. The strap connector of claim 1 wherein said body member is aluminum having an anodized surface.

3. An adjustable strap connector comprising a frame including a generally planar wall terminating in a transversely extending stationary gripping face, a cross-member extending transversely of said frame and presenting a transversely extending convex movable gripping face toward said stationary gripping face, means mounting the cross-member to the frame for limited pivotal movement and for movement toward and away from the stationary gripping face, with the bottom surface of said movable gripping face moving in a plane above and closely overlying the stationary gripping face, said cross-member having a periphery providing a plurality of discontinuous convex and fiat surfaces and being pivotable and movable toward said stationary gripping face upon the application of tension to a strap received around the cross-member and between said gripping faces to wedge and compress the strap between said gripping faces and to cause the periphery of the cross-member to engage and provide a plurality of slip-resisting inflections in the strap.

4. An adjustable strap connector comprising a frame including a generally planar wall terminating in a transversely extending stationary gripping face, a cross-member extending transversely of said frame and presenting a.

transversely extending convex movable gripping face toward said stationary gripping face, means mounting the cross-member to the frame for movement toward and away from the stationary gripping face with the bottom surface of said movable gripping face moving in a plane above and, closely overlying the stationary gripping face, said cross-member having a transversely extending ledge portion disposed above said movable gripping face whereby the periphery of said cross-member comprises a plurality of discontinuous convex and flat surfaces, said crossmember being movable toward said stationary gripping face upon the application of tension to a strap received areaeee around the cross-member and betwen said gripping faces to wedge and compress the strap between said gripping faces and to cause the periphery of the cross-member to engage and provide a plurality of slip-resisting inflections in the strap.

5. An adjustable strap connector comprising a frame including a generally planar :apertured wall having a portion terminating at the aperture in a stationary gripping face which extends transversely of the plane of said wall, a cross-member extending transversely of said frame and presenting a transversely extending movable gripping face toward said stationary gripping face, and means mounting the cross-member to the frame for movement of said movable gripping face toward and away from the stationary gripping face, with the bottom surface of the cross-member moving in a plane above the stationary gripping face to wedge and compress therebetween a strap threaded through the aperture in said planar wall and around the cross-member and between the gripping faces upon tensioning of the strap to move the cross-member toward the stationary gripping face, the distance of the bottom surface of the movable gripping face above said stationary gripping face being less than the thickness of the strap.

References Cited by the Examiner UNITED STATES PATENTS 495,633 4/93 Hoyt 24-196 946,917 1/10 Hubbard 24-494 983,718 2/11 Humphrey 24194 3,029,487 4/62 Asai 24-496 X FOREIGN PATENTS 504,129 4/20 France. 1,072,643 3/54 France.

DONLEY I. STOCKING, Primary Examiner.

2O ABRAHAM STONE, Examiner. 

3. AN ADJUSTABLE STRAP CONNECTOR COMPRISING A FRAME INCLUDING A GENERALLY PLANAR WALL TERMINATING IN A TRANSVERSELY EXTENDING STATIONARY GRIPPING FACE, A CROSS-MEMBER EXTENDING TRANSVERSELY OF SAID FRAME AND PRESENTING A TRANSVERSELY EXTENDING CONVEX MOVABLE GRIPPING FACE TOWARD SAID STATIONARY GRIPPING FACE, MEANS MOUNTING THE CROSS-MEMBER TO THE FRAME FOR LIMITED PIVOTAL MOVEMENT AND FOR MOVEMENT TOWARD AND AWAY FROM THE STATIONARY GRIPPING FACE, WITH THE BOTTOM SURFACE OF SAID MOVABLE GRIPPING FACE MOVING IN A PLANE ABOVE AND CLOSELY OVERLYING THE STATIONARY GRIPPING FACE, SAID CROSS-MEMBER HAVING A PERIPHERY PROVIDING A PLURALITY OF DISCONTINUOUS CONVEX AND FLAT SURFACES AND BEING PIVOTABLE AND MOVABLE TOWARD SAID STATIONARY GRIPPING FACE UPON THE APPLICATION OF TENSION TO A STRAP RECEIVED AROUND THE CROSS-MEMBER AND BETWEEN SAID GRIPPING FACES TO WEDGE AND COMPRESS THE STRAP BETWEEN SAID GRIPPING FACES AND TO CAUSE THE PERIPHERY OF THE CROSS-MEMBER TO ENGAGE AND PROVIDE A PLURALITY OF SLIP-RESISTING INFLECTIONS IN THE STRAP. 